<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box1 {
            width: 200px;
            height: 200px;
            background-color: #f00;
            border-radius: 20px;
        }
        .box2 {
            width: 200px;
            height: 200px;
            background-color: #0f0;
            border-radius: 50px 20px;
        }
        .box3 {
            width: 200px;
            height: 200px;
            background-color: #00f;
            border-radius: 20px 30px 40px 50px;
            /* 顺时针顺序为：左上角、右上角、右下角、左下角 */
        }
    </style>
</head>
<body>
    <div class="box1"></div>
    <div class="box2"></div>
    <div class="box3"></div>
</body>
</html>